Description from Flora of China
Perennial, aquatic, stoloniferous, numerous feathery adventitious roots arising from nodes. Culms floating, spongy, much branched. Leaf sheaths inflated, bladderlike, with transverse veinlets; leaf blades ovate-lanceolate; ligule short, membranous. Inflorescence few-spiculate panicle, base enclosed by uppermost leaf sheath. Spikelets with 1 floret, laterally compressed, floret borne upon a long slender stipe derived from floret callus, disarticulating at base of stipe, disarticulation point marked by a brown line; glumes absent; lemma lanceolate, papery, keeled, strongly 5-veined, outermost veins close to margins, apex acuminate, extended into a slender awn; palea as long as lemma body and enclosed within it, papery, 3-veined. Stamens 6. Caryopsis terete, embryo small, hilum linear, almost as long as caryopsis. x = 12.
One species: S and SE Asia, including China.